@article {&:2011:0003-6846:1375,
title = "A survival analysis of the approval of US patent applications",
journal = "Applied Economics",
parent_itemid = "infobike://routledg/raef",
publishercode ="routledg",
year = "2011",
volume = "43",
number = "11",
publication date ="2011-01-01T00:00:00",
pages = "1375-1384",
itemtype = "ARTICLE",
issn = "0003-6846",
eissn = "1466-4283",
url = "https://www.ingentaconnect.com/content/routledg/raef/2011/00000043/00000011/art00007",
doi = "doi:10.1080/00036840802600418",
author = "&, Ying Xie and Giles, David E.",
abstract = "We model the length of time that it takes for a patent application to be granted by the US Patent and Trademark Office (USPTO), conditional on the patent actually being awarded eventually. Survival analysis is applied and both the nonparametric KaplanMeier and parametric accelerated
failure time models are used to analyse the data. We find that the number of claims a patent makes, the number of citations a patent makes, the patent's technological category, and the type of applicant all have significant effects on the duration that a patent is under consideration. A log-normal
survival model is the preferred parametric specification, and the results suggest that the hazard function is nonmonotonic over time.",
}